High-frequency (10 kHz) spinal cord stimulation (SCS) as a salvage therapy for failed traditional SCS: A narrative review of the available evidence

INTRODUCTION

Traditional spinal cord stimulation (t-SCS) has been used to treat chronic pain for over 50 years. However, up to 30% of patients undergo explant, with the main indication being loss of efficacy (LoE), and few alternative treatment options exist for these patients. Strategies to mitigate LoE commonly include conversion to another type of SCS (termed 'salvage' or 'rescue'). This review summarizes the existing literature concerning the efficacy and safety of 10 kHz SCS as a salvage therapy.

METHODS

We searched PubMed, the Cochrane Library, ClinicalTrials.gov, and other sources between January 2009 and April 2021. Records were retained if the authors reported clinical outcomes with a minimum of ≥ 3 months of follow-up in patients implanted with a Senza® 10 kHz SCS system in an effort to treat t-SCS LoE.

RESULTS

Ten articles were eligible for inclusion, reporting 3 prospective studies and 7 retrospective reviews. In the single study that salvaged patients without a repeat trial prior to surgery, 81% of patients were responders (≥ 50% pain relief from baseline), with mean pain relief of 60%. Among repeat-trial studies, the responder rate ranged from 46% to 80%, and mean pain relief from 47% to 68%. No unanticipated therapy-related safety issues were reported among the included articles.

CONCLUSION

Preliminary data suggest that chronic back and/or leg pain patients with t-SCS LoE can experience improved and durable pain relief after conversion to 10 kHz SCS. However, additional research is needed to define predictors of success and establish whether salvage without a repeat trial is a viable conversion method.

The effects of selfing on multi-step adaptation

Macroevolutionary studies have estimated higher extinction rates of self-compatible lineages than self-incompatible ones. A leading explanation is that selfing may prevent adaptation, since models show that selfing can inhibit the fixation of adaptive alleles at a single locus (1-step adaptation). However, adaptation often involves changes at multiple loci (multi-step adaption), but the effects of selfing remain unclear because selfing increases homozygosity, which affects selection intensity, the effective population size, and the effective recombination rate. By modeling using population genetic models, I investigate the effects of selfing on adaption requiring fixation of 2 adaptive alleles, I show that intermediate selfing rates generally promote adaption, by increasing the fixation probability of the double-mutant haplotype once it is generated. In constant-sized populations, selfing increases the rate of adaptation through the fixation of new mutations even when both alleles are dominant. In demographically declining populations, the rescue probability rises sharply as the selfing rate increases from zero, but quickly drops to be low when it approaches 1.0. These findings are at odds with the hypothesis that higher extinction rates of self-compatible lineages result from reduced adaptive potential but may help explain why some studies have failed to detect relaxation of selection in selfers and also the prevalence of mixed-mating systems.

D-methionine administered as late as 36 hours post-noise exposure rescues from permanent threshold shift and dose-dependently increases serum antioxidant levels

OBJECTIVE

To elucidate D-methionine's (D-met) dose and time rescue parameters from steady-state or impulse noise-induced permanent threshold shift (PTS) and determine D-met rescue's influence on serum and cochlear antioxidant levels.

DESIGN

Five D-met doses at 0, 50, 100, or 200 mg/kg/dose administered starting at 1, 24, or 36 hours post steady-state or impulse noise exposure. Auditory brainstem responses at baseline and 21 days post-noise measured PTS. Serum (superoxide dismutase [SOD], catalase [CAT],, glutathione reductaseand glutathione peroxidase [GPx]) and cochlear (Glutathione [GSH] and glutathione disulphide [GSSG]) antioxidant levels measured physiological impact.

STUDY SAMPLE

Chinchillas (10/study group; 6-8/confirmatory groups).

RESULTS

D-met significantly reduced PTS for impulse noise (100 mg [2, 6, 14 and 20 kHz]; 200 mg [2, 14 and 20 kHz]) and steady-state noise (all dosing groups, time parameters and tested frequencies). PTS reduction did not significantly vary by rescue time. D-met significantly increased serum SOD (100 and 200 mg for 24 hour rescue) and GPx (50 mg/kg at 24 hour rescue) at 21 days post-noise. Cochlear GSH and GSSG levels were unaffected relative to control.

CONCLUSION

D-met rescues from steady-state and impulse noise-induced PTS even when administered up to 36 hours post-noise and dose-dependently influences serum antioxidant levels even 21 days post-noise. D-met's broad and effective dose/time window renders it a promising antioxidant rescue agent.

Microtubules self-repair in living cells

Microtubule self-repair has been studied both in vitro and in vivo as an underlying mechanism of microtubule stability. The turnover of tubulin dimers along the microtubule has challenged the pre-existing dogma that only growing ends are dynamic. However, although there is clear evidence of tubulin incorporation into the shaft of polymerized microtubules in vitro, the possibility of such events occurring in living cells remains uncertain. In this study, we investigated this possibility by microinjecting purified tubulin dimers labeled with a red fluorophore into the cytoplasm of cells expressing GFP-tubulin. We observed the appearance of red dots along the pre-existing green microtubule within minutes. We found that the fluorescence intensities of these red dots were inversely correlated with the green signal, suggesting that the red dimers were incorporated into the microtubules and replaced the pre-existing green dimers. Lateral distance from the microtubule center was similar to that in incorporation sites and in growing ends. The saturation of the size and spatial frequency of incorporations as a function of injected tubulin concentration and post-injection delay suggested that the injected dimers incorporated into a finite number of damaged sites. By our low estimate, within a few minutes of the injections, free dimers incorporated into major repair sites every 70 μm of microtubules. Finally, we mapped the location of these sites in micropatterned cells and found that they were more concentrated in regions where the actin filament network was less dense and where microtubules exhibited greater lateral fluctuations.

Significant improvements in SEIzure interVAL (time between seizure clusters) across time in patients treated with diazepam nasal spray as intermittent rescue therapy for seizure clusters

OBJECTIVE

Intermittent rescue therapy may be used for seizure clusters, which are clinical emergencies that may persist ≥24 h and increase risk of status epilepticus, emergency room visits, and reduced quality of life for patients with epilepsy. Beyond effectiveness for aborting seizure clusters, no data exist on how intermittent rescue therapy may impact the long-term natural course of seizure clusters. This novel analysis explores SEIzure interVAL (SEIVAL; time between seizure clusters) in patients from a long-term safety study of diazepam nasal spray (Valtoco) to assess SEIVAL changes with intermittent rescue therapy across time.

METHODS

Patients were aged 6-65 years. Age- and weight-based doses of diazepam nasal spray were administered during a 12-month treatment period with an optional follow-up period. SEIVAL was evaluated in patients receiving two or more doses of diazepam nasal spray using 90-day periods.

RESULTS

Of 163 treated patients, 151 had one or more SEIVALs. One hundred twenty had SEIVALs in Period 1 and one or more other periods. An increase in SEIVAL was noted from Period 1 compared with all subsequent periods (p ≤ .001). A consistent cohort (n = 76) had one or more SEIVALs in each of Periods 1-4 (360 days); mean SEIVALs increased significantly (p < .01) from 12.2 days (Period 1) to 25.7 days (Period 4). Similar SEIVAL patterns occurred when repeat doses within a seizure cluster were eliminated and irrespective of age group, treatment duration, and change to concomitant medications. In adults, Quality of Life in Epilepsy scores were maintained with increased SEIVALs.

SIGNIFICANCE

Across 12 months, increases in SEIVAL were demonstrated in patients using diazepam nasal spray for seizure cluster treatment in a phase 3 safety study. Increased time between seizure clusters may reflect a previously unrecognized beneficial effect of intermittent rescue therapy. These results generate a range of biological and behavioral hypotheses and warrant exploration of the impact of intermittent rescue therapy.

Predicting outcome in acute respiratory admissions using patterns of National Early Warning Scores

AIMS

Accurately predicting risk of patient deterioration is vital. Altered physiology in chronic disease affects the prognostic ability of vital signs based early warning score systems. We aimed to assess the potential of early warning score patterns to improve outcome prediction in patients with respiratory disease.

METHODS

Patients admitted under respiratory medicine between April 2015 and March 2017 had their National Early Warning Score 2 (NEWS2) calculated retrospectively from vital sign observations. Prediction models (including temporal patterns) were constructed and assessed for ability to predict death within 24 hours using all observations collected not meeting exclusion criteria. The best performing model was tested on a validation cohort of admissions from April 2017 to March 2019.

RESULTS

The derivation cohort comprised 7,487 admissions and the validation cohort included 8,739 admissions. Adding the maximum score in the preceding 24 hours to the most recently recorded NEWS2 improved area under the receiver operating characteristic curve for death in 24 hours from 0.888 (95% confidence interval (CI) 0.881-0.895) to 0.902 (95% CI 0.895-0.909) in the overall respiratory population.

CONCLUSION

Combining the most recently recorded score and the maximum NEWS2 score from the preceding 24 hours demonstrated greater accuracy than using snapshot NEWS2. This simple inclusion of a scoring pattern should be considered in future iterations of early warning scoring systems.

Recognizing seizure clusters in the community: The path to uniformity and individualization in nomenclature and definition

Seizure emergencies experienced by patients with epilepsy include status epilepticus and seizure clusters. Although an accepted definition of status epilepticus exists, no clear consensus definition of seizure clusters has emerged; this is further complicated by the appearance in the literature of various empirically based definitions that have been developed for clinical trial study designs. In general, patients with intractable epilepsy have been shown to have a significant risk for acute episodes of increased seizure activity called seizure clusters (also referred to as acute repetitive seizures, among other terms) that differ from their usual seizure pattern. Duration (e.g., number of hours or days) is often included in the definition of a seizure cluster; however, the duration may vary among patients, with some seizure clusters lasting ≥24 h and requiring long-acting treatment for this period. In addition to seizure cluster duration, the time between seizures and possible acceleration in seizure frequency during the cluster may be important variables. The recognition and treatment of seizure clusters require urgent action because episodes that are not quickly and appropriately treated may lead to injury or progress to status epilepticus or potentially death. Most seizure clusters occur outside a medical facility (in the community) and treatment is usually administered by nonmedical individuals; therefore, health care providers may benefit from a clear description of these potential seizure emergencies that they can then use to educate patients and caregivers on the prompt and appropriate identification of seizure clusters and administration of rescue therapy. Here we explore why greater uniformity is needed in the discussion of seizure clusters. This exploration examines epidemiologic studies of seizure clusters and status epilepticus, inconsistencies in nomenclature and definitions for seizure clusters, practical application of seizure cluster terminology, and the potential use of acute seizure action plans and patient-specific individualized definitions in the clinical setting.

Reproduction and pathogenesis of short beak and dwarfish syndrome in Cherry Valley Pekin ducks infected with the rescued novel goose parvovirus

Since the outbreak of short beak and dwarfish syndrome (SBDS) in Cherry Valley Pekin ducks in China, novel goose parvovirus (NGPV) has been isolated. Till now, little is known about the NGPV pathogenesis toward Cherry Valley Pekin ducks. Besides, due to detection of duck circovirus co-infection in SBDS clinical cases, whether sole NGPV infection can reproduce all the typical symptoms of SBDS remains unclear. In this study, based on the NGPV isolate SDJN19, an infectious plasmid clone pJNm containing the entire SDJN19 genome was constructed. Transfection of pJNm in embryonated duck eggs resulted in generation of the infectious virus carrying the genetic marker, named rJNm. rJNm infection of 2-day-old Cherry Valley Pekin ducks reproduced all the typical signs of SBDS, including beak atrophy, tongue protrusion, and growth retardation. rJNm can infect Cherry Valley Pekin ducks through the horizontal transmission route, and the infected ducks exhibited the characteristic SBDS symptoms. A high level of serum precipitation antibodies (above 5log₂) were induced in the surviving ducks, however, high viral loads were still detected in the duck organs, suggesting persistent NGPV infection in ducks. By incorporating the homologous Rep1 and VP1 gene from classical GPV, two chimeric viruses rJN-cVP1 and rJN-cRep1 were generated. Duck infection tests revealed that the non-structural protein Rep1 played a crucial role in the NGPV pathogenicity. The present result lays a solid foundation for further exploring how the Rep protein contributes to the NGPV pathogenesis.

Patient monitoring, wearable devices, and the healthcare information ecosystem

Conventional patient vital signs monitoring fails to detect many signs of patient deterioration, including those in the critical postoperative period. Wearable monitors can allow continuous vital signs monitoring, send data wirelessly to the electronic healthcare record, and reduce the number of unplanned admissions to intensive care.

Second line therapy for Helicobacter pylori eradication: state of art

Helicobacter pylori (H. pylori) is a Gram negative spiraliform bacterium who colonizes the human stomach. It is the most common cause of chronic gastritis, peptic ulcer, and gastric carcinoma. The eradication therapy is based on the combination of a proton pump inhibitor and several antibiotics such as amoxicillin, metronidazole, clarithromycin, levofloxacin or tetracycline. The most commonly used regimens for eradication in the first line are triple, sequential and concomitant therapy, despite the last European Guidelines suggesting a quadruple therapy already at the first attempt in areas with high resistance rates. However, the rise in antibiotic resistance is the main reason for a marked increase in first-line therapy failure. Clarithromycin resistancea , is especially acknowledged as the most important event resulting in failure. Up to 20% of patients are intended not to eradicate, therefore they will need a second line therapy. Currently, the most used rescue regimens are levofloxacin-based triple therapy and bismuth-containing quadruple therapy, despite guidelines suggesting to use a combination of antibiotics that have not been included in previous treatments. Nitazoxanide is a novel antibiotic with promising results. Additionally, an interesting field worth of investigation is the antibiotic susceptibility based approach, which could help to choose antibiotics with confirmed effectiveness in vitro. Analysis of antibiotic resistance may be performed by both bacterial culture and molecular biology techniques, able to detect point mutations conferring resistance. This is a particularly interesting approach, since it may personalize the therapy, thus optimizing the regimen and maximizing the probability of success.

Experience with Rifabutin-Containing Therapy in 500 Patients from the European Registry on Helicobacter pylori Management (Hp-EuReg)

BACKGROUND

First-line Helicobacter pylori (H. pylori) treatments have been relatively well evaluated; however, it remains necessary to identify the most effective rescue treatments. Our aim was to assess the effectiveness and safety of H. pylori regimens containing rifabutin.

METHODS

International multicentre prospective non-interventional European Registry on H. pylori Management (Hp-EuReg). Patients treated with rifabutin were registered in AEG-REDCap e-CRF from 2013 to 2021. Modified intention-to-treat and per-protocol analyses were performed. Data were subject to quality control.

RESULTS

Overall, 500 patients included in the Hp-EuReg were treated with rifabutin (mean age 52 years, 72% female, 63% with dyspepsia, 4% with peptic ulcer). Culture was performed in 63% of cases: dual resistance (to both clarithromycin and metronidazole) was reported in 46% of the cases, and triple resistance (to clarithromycin, metronidazole, and levofloxacin) in 39%. In 87% of cases rifabutin was utilised as part of a triple therapy together with amoxicillin and a proton-pump-inhibitor, and in an additional 6% of the patients, bismuth was added to this triple regimen. Rifabutin was mainly used in second-line (32%), third-line (25%), and fourth-line (27%) regimens, achieving overall 78%, 80% and 66% effectiveness by modified intention-to-treat, respectively. Compliance with treatment was 89%. At least one adverse event was registered in 26% of the patients (most frequently nausea), and one serious adverse event (0.2%) was reported in one patient with leukopenia and thrombocytopenia with fever requiring hospitalisation.

CONCLUSION

Rifabutin-containing therapy represents an effective and safe strategy after one or even several failures of H. pylori eradication treatment.

Porcine circovirus 4 rescued from an infectious clone is replicable and pathogenic in vivo

Porcine circovirus 4 (PCV4) is a newly identified porcine circovirus in pigs, belonging to the Circoviridae family Circovirus genus. The virus was detected in all age groups and aborted fetuses. However, the virus hasn't been isolated from the field samples to date. In this study, PCV4 was successfully rescued from an infectious clone. The rescued PCV4 was replicable in PK-15 cells and piglets, which can be detected in almost all the collected samples of the challenge groups. No obvious clinical symptoms were observed in both sham- and PCV4-inoculated piglets during the whole experiment. However, visible pathological changes were found in several organs of the PCV4-inoculated piglets, indicating that rescued PCV4 was pathogenic in piglets. Furthermore, the viremia, PCV4-specific antibody, and up-regulated cytokines/chemokines were also detected in the PCV4-inoculated groups, suggesting effective humoral and cellular immune responses were stimulated in response to the virus challenge. The PCV4 rescued in this study may provide the basis for preventive and controlling the disease, and vaccine development. This article is protected by copyright. All rights reserved.

Use of second doses of Valtoco® (diazepam nasal spray) across 24 hours after the initial dose for out-of-hospital seizure clusters: Results from a phase 3, open-label, repeat-dose safety study

Objective

An exploratory analysis from a long‐term, phase 3, open‐label, repeat‐dose safety study of diazepam nasal spray for acute treatment of seizure clusters assessed the use of a second dose up to 24 hours after the initial dose and effectiveness in potentially reducing the number of seizures.

Methods

Seizures and doses were recorded in diaries.

Results

Of 175 patients enrolled, 163 received ≥1 dose of diazepam nasal spray and were included in the safety population; those patients received a total of 4390 doses for a total of 3853 seizure clusters. Less than half of these patients used a second dose a least once during the study (79 patients [48.5%]), with a total of 485 second doses for seizure clusters (12.6% of all seizure clusters). Among these 79 patients, 33 (41.8%) used only one second dose during the study (range: 1–82). The proportion of seizure clusters treated with a second dose over time was consistently low across 24 h: 0–4 h, 152 (3.9%); 4–6 h, 72 (1.9%); 6–8 h, 39 (1.0%); 8–12 h, 55 (1.4%); 12–16 h, 42 (1.1%); 16–20 h, 42 (1.1%); 20–24 h, 83 (2.2%). Rates of treatment‐emergent adverse events (TEAEs) and treatment‐related TEAEs occurring within 1 day of a second dose were low (15.2% and 5.1%, respectively).

Significance

Patients with epilepsy may experience seizure clusters lasting up to 24 hours, and little is known about the effectiveness of rescue therapies for that duration. The current labeling of the US Food and Drug Administration (FDA)–approved outpatient treatments for seizure clusters (rectal diazepam, intranasal midazolam, and diazepam nasal spray) allows for a second dose, if needed, for control. These findings support the safety profile of second doses, and the low use supports the effectiveness of diazepam nasal spray across 24 hours.

Nutritional Approaches as a Treatment for Impaired Bone Growth and Quality Following the Consumption of Ultra-Processed Food

The severe impairment of bone development and quality was recently described as a new target for unbalanced ultra-processed food (UPF). Here, we describe nutritional approaches to repair this skeletal impairment in rats: supplementation with micro-nutrients and a rescue approach and switching the UPF to balanced nutrition during the growth period. The positive effect of supplementation with multi-vitamins and minerals on bone growth and quality was followed by the formation of mineral deposits on the rats' kidneys and modifications in the expression of genes involved in inflammation and vitamin-D metabolism, demonstrating the cost of supplementation. Short and prolonged rescue improved trabecular parameters but incompletely improved the cortical parameters and the mechanical performance of the femur. Cortical porosity and cartilaginous lesions in the growth-plate were still detected one week after rescue and were reduced to normal levels 3 weeks after rescue. These findings highlight bone as a target for the effect of UPF and emphasize the importance of a balanced diet, especially during growth.

Targeted Genetic Reduction of Mutant Huntingtin Lessens Cardiac Pathology in the BACHD Mouse Model of Huntington's Disease

Individuals affected by Huntington's disease (HD) present with progressive degeneration that results in a wide range of symptoms, including cardiovascular (CV) dysfunction. The huntingtin gene (HTT) and its product are ubiquitously expressed, hence, the cardiomyopathy could also be driven by defects caused by its mutated form (mHTT) in the cardiomyocytes themselves. In the present study, we sought to determine the contribution of the mHTT expressed in the cardiomyocytes to CV symptoms. We utilized the BACHD mouse model, which exhibits many of the HD core symptoms, including CV dysfunction. This model allows the targeted genetic reduction of mHTT expression in the cardiomyocytes while maintaining the expression of the mHTT in the rest of the body. The BACHD line was crossed with a line of mice in which the expression of Cre recombinase is driven by the cardiac-specific alpha myosin-heavy chain (Myh6) promoter. The offspring of this cross (BMYO mice) exhibited a dramatic reduction in mHTT in the heart but not in the striatum. The BMYO mice were evaluated at 6 months old, as at this age, the BACHD line displays a strong CV phenotype. Echocardiogram measurements found improvement in the ejection fraction in the BMYO line compared to the BACHD, while hypertrophy was observed in both mutant lines. Next, we examined the expression of genes known to be upregulated during pathological cardiac hypertrophy. As measured by qPCR, the BMYO hearts exhibited significantly less expression of collagen1a as well as Gata4, and brain natriuretic peptide compared to the BACHD. Fibrosis in the hearts assessed by Masson's trichrome stain and the protein levels of fibronectin were reduced in the BMYO hearts compared to BACHD. Finally, we examined the performance of the mice on CV-sensitive motor tasks. Both the overall activity levels and grip strength were improved in the BMYO mice. Therefore, we conclude that the reduction of mHtt expression in the heart benefits CV function in the BACHD model, and suggest that cardiomyopathy should be considered in the treatment strategies for HD.

Methyl mercaptan gas: mechanisms of toxicity and demonstration of the effectiveness of cobinamide as an antidote in mice and rabbits

CONTEXT

Methyl mercaptan (CH₃SH) is a colorless, toxic gas with potential for occupational exposure and used as a weapon of mass destruction. Inhalation at high concentrations can result in dyspnea, hypoventilation, seizures, and death. No specific methyl mercaptan antidote exists, highlighting a critical need for such an agent. Here, we investigated the mechanism of CH₃SH toxicity, and rescue from CH₃SH poisoning by the vitamin B₁₂ analog cobinamide, in mammalian cells. We also developed lethal CH₃SH inhalation models in mice and rabbits, and tested the efficacy of intramuscular injection of cobinamide as a CH₃SH antidote.

RESULTS

We found that cobinamide binds to CH₃SH (K_d = 84 µM), and improved growth of cells exposed to CH₃SH. CH₃SH reduced cellular oxygen consumption and intracellular ATP content and activated the stress protein c-Jun N-terminal kinase (JNK); cobinamide reversed these changes. A single intramuscular injection of cobinamide (20 mg/kg) rescued 6 of 6 mice exposed to a lethal dose of CH₃SH gas, while all six saline-treated mice died (p = 0.0013). In rabbits exposed to CH₃SH gas, 11 of 12 animals (92%) treated with two intramuscular injections of cobinamide (50 mg/kg each) survived, while only 2 of 12 animals (17%) treated with saline survived (p = 0.001).

CONCLUSION

We conclude that cobinamide could potentially serve as a CH₃SH antidote.

Evaluation of a Novel Left Ventricular Assist Device for Resuscitation in an Animal Model of Ventricular Fibrillation Cardiac Arrest

We evaluated an independently developed novel percutaneous implantable left ventricular assist device for resuscitation in a pig model of ventricular fibrillation cardiac arrest. The model was established in 10 domestic pigs by blocking the anterior descending coronary artery with a balloon after anesthesia. With ventilator-assisted ventilation, the independently developed percutaneous implantable left ventricular assist device was inserted via the femoral artery to assist circulation. According to whether effective circulatory support was achieved, the pigs were randomly divided into an experimental group and a control group. The experimental group was subjected to insertion of the assist device and received continuous circulatory support. The control group underwent insertion of the assist device; however, it did not start it within 15 minutes. For all animals, if successful rescue was achieved (sinus rhythm restoration within 15 minutes and maintenance for over 5 minutes), circulatory support was stopped, and the arterial blockage was removed. If sinus rhythm was not restored within 15 minutes, electric defibrillation, adrenaline injection, and removal of the arterial blockage were performed, and circulatory support was provided until sinus rhythm recovered. A determination of failed rescue was made when sinus rhythm was not restored after 1 hour. All successfully rescued animals were fed for 1 week. There were no significant differences in baseline data between the groups. All animals underwent successful novel left ventricular assist device implantation through the femoral artery. The rescue rate was significantly higher in the experimental group than in the control group (80% vs. 0%, [Formula: see text]). All successfully rescued animals survived after 1 week of feeding, and no eating or movement abnormalities were observed. We conclude that this independently developed percutaneous implantable left ventricular assist device can be conveniently and rapidly implanted through the femoral artery and can maintain basic circulatory perfusion during resuscitation in an animal model of cardiac arrest.

Motor usage imprints microtubule stability along the shaft

Tubulin dimers assemble into dynamic microtubules, which are used by molecular motors as tracks for intracellular transport. Organization and dynamics of the microtubule network are commonly thought to be regulated at the polymer ends, where tubulin dimers can be added or removed. Here, we show that molecular motors running on microtubules cause exchange of dimers along the shaft in vitro and in cells. These sites of dimer exchange act as rescue sites where depolymerizing microtubules stop shrinking and start re-growing. Consequently, the average length of microtubules increases depending on how frequently they are used as motor tracks. An increase of motor activity densifies the cellular microtubule network and enhances cell polarity. Running motors leave marks in the shaft, serving as traces of microtubule usage to organize the polarity landscape of the cell.

Rescue Endovascular Treatment for Emergent Large Vessel Occlusion With Underlying Intracranial Atherosclerosis: Current State and Future Directions

Intracranial atherosclerosis (ICAS) is one of the most common causes of stroke worldwide and is associated with high risk of stroke recurrence. While the most common clinical presentation is acute–subacute transient ischemic attack or ischemic stroke, occasionally, patients with underlying ICAS present with acute occlusion of the affected vessel. Diagnosis and endovascular management of ICAS-related emergent large vessel occlusion (ELVO) can be challenging. Herein, we review the current evidence supporting endovascular management of ICAS-related ELVO and discuss future directions.

An Analysis of Demographic and Triage Assessment Findings in Bushfire-Affected Koalas (Phascolarctos cinereus) on Kangaroo Island, South Australia, 2019-2020

Simple Summary

In the 2019–2020 Australian bushfires, Kangaroo Island, South Australia, experienced catastrophic bushfires that burnt approximately half the island, with an estimated 80% of the koala population lost. During and after the fires, koalas presented to a designated triage facility over a span of 10 weeks, with 50.2% during the first 14 days of the bushfire response (304 records available). Burns were observed in 67.4% of koalas, with the majority (60.9%) classified as superficial burns, primarily affecting the limbs and face. Poor body condition was recorded in 74.6% of burnt koalas and dehydration in 77.1%. Negative final outcomes (death or euthanasia, either at triage or at a later date) occurred in 45.6% of koalas and were significantly associated with higher mean burn score, maximum burn severity, number of body regions burnt, poor body condition score, and dehydration severity. The findings of this retrospective study may assist clinicians in the field with decision making when triaging koalas in future fire rescue efforts.

Abstract

In the 2019–2020 Australian bushfires, Kangaroo Island, South Australia, experienced catastrophic bushfires that burnt approximately half the island, with an estimated 80% of the koala population lost. During and after the event, rescued koalas were triaged at a designated facility and a range of initial data were recorded including rescue location and date, sex, estimation of age, body condition and hydration, and assessment of burn severity (n = 304 records available). Koalas were presented to the triage facility over a span of 10 weeks, with 50.2% during the first 14 days of the bushfire response, the majority of which were rescued from regions of lower fire severity. Burns were observed in 67.4% of koalas, with the majority (60.9%) classified as superficial burns, primarily affecting the limbs and face. Poor body condition was recorded in 74.6% of burnt koalas and dehydration in 77.1%. Negative final outcomes (death or euthanasia, at triage or at a later date) occurred in 45.6% of koalas and were significantly associated with higher mean burn score, maximum burn severity, number of body regions burnt, poor body condition score, and dehydration severity. The findings of this retrospective study may assist clinicians in the field with decision making when triaging koalas in future fire rescue efforts.

Ultrasound to the Rescue: Management of Looped Guidewire during Hemodialysis Catheter Insertion in the Left Internal Jugular Vein

Hemodialysis catheters are commonly placed in the major central vein for the purpose of dialysis. Coiling or looping of guidewire is a rare but reported complication of a central vascular catheter insertion. We report a case in which we encountered a rare complication of looping of the guidewire used for dialysis catheter placement and how we correctly diagnosed and repositioned it under ultrasound guidance. A 68-yearold man diagnosed with Carcinoma of Pyriform Fossa admitted in our ICU had Acute Renal Failure. An attempt to insertion of hemodialysis catheter in left internal jugular vein was made. Following successful puncture, the guide wire was threaded through needle. After five centimeter length of guide wire was threaded, resistance was felt and a loop of guidewire was visualized which was abutting the posterior wall of vein in out-of-plane view, creating a dual-point echogenicity. Under ultrasound guidance, we slowly pulled out the guidewire till the loop disappeared.The catheter was then inserted without repeat puncture of the vessel, thus preventing chance of thrombosis by repeated attempts. Real time USG guidance not only improves the success rates but also decreases the number of attempts and complications related to hemodialysis catheterization. Moreover, it benefits the patients by reducing the risks and discomforts of the procedure by reducing the duration of cannulation. The intelligent use of real-time ultrasound guidance in each step of the central venous catheterization is absolutely the need of the hour to prevent catastrophic yet preventable complications.

Diversity and Similarity of Termination and Ribosome Rescue in Bacterial, Mitochondrial, and Cytoplasmic Translation

When a ribosome encounters the stop codon of an mRNA, it terminates translation, releases the newly made protein, and is recycled to initiate translation on a new mRNA. Termination is a highly dynamic process in which release factors (RF1 and RF2 in bacteria; eRF1•eRF3•GTP in eukaryotes) coordinate peptide release with large-scale molecular rearrangements of the ribosome. Ribosomes stalled on aberrant mRNAs are rescued and recycled by diverse bacterial, mitochondrial, or cytoplasmic quality control mechanisms. These are catalyzed by rescue factors with peptidyl-tRNA hydrolase activity (bacterial ArfA•RF2 and ArfB, mitochondrial ICT1 and mtRF-R, and cytoplasmic Vms1), that are distinct from each other and from release factors. Nevertheless, recent structural studies demonstrate a remarkable similarity between translation termination and ribosome rescue mechanisms. This review describes how these pathways rely on inherent ribosome dynamics, emphasizing the active role of the ribosome in all translation steps.

Quality Indicators for Avalanche Victim Management and Rescue

Decisions in the management and rescue of avalanche victims are complex and must be made in difficult, sometimes dangerous, environments. Our goal was to identify indicators for quality measurement in the management and rescue of avalanche victims. The International Commission for Mountain Emergency Medicine (ICAR MedCom) convened a group of internal and external experts. We used brainstorming and a five-round modified nominal group technique to identify the most relevant quality indicators (QIs) according to the National Quality Forum Measure Evaluation Criteria. Using a consensus process, we identified a set of 23 QIs to measure the quality of the management and rescue of avalanche victims. These QIs may be a valuable tool for continuous quality improvement. They allow objective feedback to rescuers regarding clinical performance and identify areas that should be the foci of further quality improvement efforts in avalanche rescue.

Long-term results of rescue photodynamic therapy for type 1 neovascularization refractory to anti-vascular endothelial growth factor

PURPOSE

To evaluate long-term results of photodynamic therapy (PDT) as a rescue treatment in patients with type 1 neovascularization refractory to intravitreal anti-vascular endothelial growth factor (VEGF).

METHODS

Patients who underwent reduced-fluence PDT for refractory type 1 neovascularization, which showed persistent subretinal and/or intraretinal fluid after three or more consecutive anti-VEGF treatments, and were followed up for ≥24 months were reviewed.

RESULTS

Seventy-eight eyes of 78 patients were included, and 37 (47%) were classified as polypoidal choroidal vasculopathy (PCV). The mean number of anti-VEGF injections before rescue PDT was 8.5 ± 5.4, and the mean follow-up period after rescue PDT was 74.0 ± 29.4 months. At 3 months after rescue PDT, exudation completely resolved in 55 (71%) patients and vision significantly improved (p = 0.021). Resolution of exudation was associated with choroidal vascular hyperpermeability [odds ratio (OR), 3.82; p = 0.031] and lower maximal height of pigment epithelial detachment (OR, 0.69; p = 0.018). In these patients, exudation recurred in 49 (89%) after mean period of 13.5 months. Vision significantly worsened at 24 months after rescue PDT, and thereafter, and the vision decrease was more prominent in patients with PCV. Rescue PDT could be repeated for recurrent or persistent exudation without increasing the risk of complications.

CONCLUSION

In patients with type 1 neovascularization refractory to anti-VEGF, reduced-fluence PDT is an effective and safe rescue treatment. Therapeutic efficacy wore off during long-term follow-up, but rescue PDT may be repeated safely.

Salvaging Pull-Out Strength in a Previously Stripped Screw Site: A Comparison of Three Rescue Techniques

Screw stripping during bone fixation is a common occurrence during operations that results in decreased holding capacity and bone healing. We aimed to evaluate the rescue of the stripped screw site using screws of different dimensions. Five screw configurations were tested on cadaveric specimens for pull-out strength (POS). The configurations included a control screw tightened without stripping, a configuration voluntarily stripped and left in place, and three more configurations in which the stripped screws were replaced by a different screw with either increased overall length, diameter, or thread length. Each configuration was tested five times, with each screw tested once. The POS of the control screw, measured to be 153.6 ± 27 N, was higher than the POS measured after stripping and leaving the screw in place (57.1 ± 18 N, p = 0.001). The replacement of the stripped screw resulted in a POS of 158.4 ± 64 N for the screw of larger diameter, while the screws of the same diameter but increased length or those with extended thread length yielded POS values of 138.4 ± 42 and 185.7 ± 48 N, respectively. Screw stripping is a frequent intraoperative complication that, according to our findings, cannot be addressed by leaving the screw in place. The holding capacity of a stripped screw implanted in cancellous bone can successfully be restored with a different screw of either larger diameter, longer length, or extended thread length.